Alexander



A. McL. NECOLSON. ELECTRIC WAVE REPEATING APPARATUS.

APPLICATION FILED OCT- 26, 1916.

- Patented June 24, 1919.

v l u-7,1311 l/llrfll m //1 WM for: Alexa/1d #72411 1 Mao/ran.

UNITED-STATES PATENT OFFICE.

ALEXANDER MOLEAN NICOLSON, OF NEW YORK, N. Y., AS SIGNOB TO WESTERN ELECTRIC COMPANY, INCORPORATED, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

ELEGTBIC-wAVE-REBEATING Arrmrus.

Specification of Letters l'atentp Pat nt d J 24 1919 Application filed October 26, 1916. Serial No. 127,916.

To all whom it may concern Be it known that I, ALEXANDER MCLEAN NICOLSON, a subject of the King of Great Britain, residing at New York, in the county of New York and State of New York, have invented certain new and useful Improvements in Electric-Wave-Repeating Apparatus, of which the following is a full, clear, concise, and exact description.

This invention relates to electric wave repeating apparatus, and particularly to the use of vacuum discharge repeaters, as exemplified by the so-called audion, for repeating and amplifying in an output circuit waves of electric energy received in an input circuit. An object is to improve the quality of transmission by producing, in the output circuit, electric waves free from distortion with respect to the input waves.

This invention is especially useful in telephone and telegraph systems for repeating and amplifying alternating current waves of small magnitude. p The principal parts of an audion element or structure are a heated filament or other source of electrons, an anode usually called a plate, and an electrode preferably located intermediate between the filament and the plate, said electrode being usually called a grid. These are preferably included in an evacuated vessel. The "characteristic fea tures of the audion are that current can fiow m one direction only in the space current stream, and that the strength of the current in the stream flowing from its source to the plate is modified byelectrostatic rather than by electromagnetic force.

A sim le arrangement-fo using a single audion e eemnt as a repeater is as follows: The input circuit has one terminal connected to the filament and the other to the grid, while the output circuit has one termmal connected to the filament and the other to the plate. Repeating coils are preferably employed in the input and output circuits respectively, and a batteryis included in the output circuit in series with the primary winding of the output repeatin coil. The audion repeater as'thus used, alt ou-gh a powerful amplifying agent, does not give in the output circuitv a perfect reproduction of-the electric waves received in the input circuit. This is due to the fact that the relation between the plate current and the grid voltage is not expressed by a Feb. 16, 1915 and patent Arnold, 1,128,279,

Feb. 15,1915.

This invention will be more clearly understood by reference to the accompanying drawing, in which Figure 1 shows a perspective view of the device of this invention with certain parts broken away, and Fig. 2 illustrates diagrammatically how such a device may be employed in a circuit amplifying telephonic currents.

In Fig. 1, 3 is an evacuated vessel within which are two audion elements mounted in a suitable manner, consisting of the anode or plate members 4 and 5, the two cathodes 6 and 7, and an input electrode or grid 8, common to both audion elements.

In Fig. 2, the structure of Fig. 1 is shown.

the oscillations to be amplified. The other arm of the input circuit comprises the cathode 7, the portion 17 of the secondary winding of transformer 15, the battery 13 and the common grid 8. Cathode 6 is also connected through the primary winding 19 of the output transformer 20, and through bat tery 21 to the anode 4. Similarly, cathode 7 is connected through primary winding 22 and battery 23 to anode 5. Windings 19-and 22 are dilferentially related to the secondary 24:, so that the resultant efiect of equal currents in coils 19 and 22 is zero in coil 24.

The cathodes 0r filaments Q and 7 are heated by the batteries 11 and 12, respectively, and

then become thermionically active, thereby causing the space current to flow to their re spective anodes. Batteries 21, 23 are, of course, sopoled asto make anodes 4 and 5 potential of filament 6 will decrease.

- two coils 14 and 1 Y In considering the operation of the dev1ce,

it is known that raising the potential of. a charged body,located hear a heated cathode, ingeneral serves to increase the space current between the cathode and anode main- .tained positive thereto, and conversely, that lowering the potential of a charged body will in general decrease the space current. Suppose, for example, thatv at a given 1nstant of time the character of the signalwave impressed on coils 17 and 1a from primary coil 16 is such as to increase the poten tial of filament 7; if such is the case,'the

grid 8 then will be lowered in potential with respect to the filament 7 but raised in potential with respect to the filament 6. Consequently, the thermionic current to the plate 5 fromthe cathode 7 will be decreased by the presence of the grid 8. Similarly, the thermionic current from filament 6 to plate 4 will be increased by the presence of the grid 8. Hence, in the output circuit containing the coil 22, there will be a decrease in current, and in the output circuit containing the coil 19 there will be an increase in the current. When the character of the signal'wave at a given instant is such as to make filament 7 at a lower potential than filament 6, by similar reasoning, there will. be an increase in the current through coil 22 and. a decrease through coil 19. These current changes are additive in their effect on secondary winding 24. Hence, it follows that an amplified current results in coil 24 having the same frequency and wave form as the ctt'rrents initially impressed on winding 16. It is to be understood that the elimination of distortion in the repeating of current waves is not the only use to which the novel form of the evacuated vessel may be put. As an example of another use, it is apparent that if the vesselis connected up in a circuit in which one of the coils 19 or 22 is reversed, the tube may operate as arectifier of alternating current.

What is claimed is:

1. An evacuated vessel containing a plurality of space current paths having electrodes individual to each of said paths, and

a controlling electrode common to said paths.

2 In an electric wave repeating. appa-.

. ratus, an evacuated vessel containing a pluralityof, filaments, output electrodes individual to said filaments, and an input electrode common to said filaments.

The

3. In an electric wave repeating apparatus, an evacuated vessel having a plurality of audion elements comprising two anodes and their corresponding filaments located between said anodes, and a grid between said filaments.

' 4. In an electric wave repeating apparatus, the combination of two repeating elements each comprising a filament, an anode, a space current stream between said electrodes and controlling means for said space current streams, an input repeating coil the secondary winding of which is connected at an intermediate point to said controlling means and at its 0 posite terminals to said filaments respectivel y.

5. In an electric wave repeating appa-v ratus, the combination of an evacuated vessel containing two cathodes and two anodes,

and a grid common to said elements, an input repeating coil having its secondary winding divid cd said common grid being connected to an intermediate point of said divided secondary winding and the ends of said secondary winding being connected to said cathodes respectively, an output repeating coil having two primary windings oppositely connected, each in series with one of said cathodes anode.

6. In an energy translating device, an evacuated vessel comprising two filaments, two anodes and a grid common to said elements, an input repeating coil having its secondary winding divided, said common grid being connected to an intermediate point of said divided secondary winding and the ends of said secondary winding being connected to and its corresponding said filaments respectively, a divided output repeating coil having two primar windings oppositely connected, a battery or each portion of said output circuit, each primary winding being connected in series with one of said batteries, one of said filaments and 1ts corresponding anode.

7. An evacuated vessel containing a plurality of space current paths each comprising a cathode, and an auxiliary electrode intheir corresponding cathodes located between saidanodes and agrid between said cathodes. I

. 10. In an electric wave repeating apparatus, means for repeating an alternating current wave without distortion-comprising an evacuated vessel'containing a plurality of space current paths having electrodes individual to each of said paths and a variable potential cold control-electrode common to said paths.

11. In an electric wave repeating appa ratus, means for repeating an alternating current wave without distortion comprising an evacuated vessel containing a plurality of space current paths having electrodes individual to each of said paths and a controlling electrode separating said paths.

12. In an electric wave repeating apparatus, the combination of two repeating elements, each comprising a cathode, an anode, with means for establishing a space current stream between said electrodes, acontrolling means for said space current streams, and an impedance, said cathodes 'being connected to the terminals of said'impedance and said controlling means being connected to an intermediate point of said impedance.

13, An electric wave repeatin' apparatus comprising divided input and ivided output circuits, means for producing two space current paths, said paths being oppositely included in said output circuit, and a variable potential cold control electrode common to said paths.

14. In an electric wave repeating apparatus, the combination of two repeatin elements comprising an input electro e, a,

cathode and an anode for each said element, anmput repeating coil the secondary winding of which is connected at an intermediate point to said input electrode and its opposite terminals to said cathodes respectively.

15. In an electric wave repeating apparatus, the combination of two repeating ele ments comprising an anode and a cathode for each said element, an input electrode common to said elements, an input repeating coil, an output repeating coil, the terminals of the secondary winding of. said input repeating coil being connected to said cathodes respectively and the primary winding of said output repeating coil being divided and the divisions connected to said repeating'elements respectively.

16. In an electric wave repeating apparatus, the combination with input and output circuits and a repeating coil in each of said circuits, of two repeatlng elements together comprising a common input electrode, an anode for each element, and two cathodes, said input electrode being connected to an intermediate point in the secondary winding of the input repeating coil, the primarywinding of said output repeating coil being divided, the two divisions being connected respectively'between the cathode and anode of the two repeating elements.

' In witness whereof, I hereunto subscribe myna-me this 25th day of October A. 1)., 1916.

ALEXANDER MGLEAN NICOLSON. 

